Perspectives from China

I spent the last three weeks in China partly for a conference, partly for a vacation, and partly for a rest. In catching up over the last couple of days, I notice that the break has given me a slightly different perspective on a couple of issues that are relevant here.

First off, the conference I attended was on paleoceanography and there were was a lot of great new science presented, particularly concerning the Paleocene-Eocene Thermal Maximum (around 55 million years ago), and on past changes to tropical rainfall patterns (see this week’s Nature) – two issues where there is a lot of relevance for climate change and its impacts today. I’ll discuss the new data in separate posts over the next few weeks, but for now I’ll just mention a topic that came up repeatedly in conversations over the week – that was how to improve the flow of information from the paleo community to the wider climate community, as represented by the IPCC for instance.

There was a palpable sense that insights from paleo-climate (in this case referring mainly to the ocean sediment record rather than ice cores or records from the last millennium) were not being given their due, and in fact were frequently being misused. In a panel discussion (hosted by Stefan), people lamented the lack of ‘synthesis’ that would be useful for the outside community, while others stressed (correctly) that synthesis is hard and frankly not well regarded within the community or their funders. I think this is a general problem; many of the incentives for success within an academic field – the push for novel techniques, the ownership of specific slices of data, the desire to emulate the paths to success of the previous generation – actually discourage work across the field that pulls together disparate sources of information.

In the paleo-oceanography case, this exhibits itself in the overwhelming focus on downcore records (the patterns of change at a single point through time) and the relative lack of integrated products that either show spatial patterns of change at a single time, or that try to extract common elements from multiple events in the past. There are of course numerous exceptions – the MARGO project that compiled records from the peak of the last ice age, or the work of PMIP for the mid-Holocene – but their visibility makes their uniqueness all the more obvious. There were no ideas presented that would fix this overnight, but the discussions showed that the community realises that there is a problem – even if the solutions are elusive.

My second thought on China came from travelling through some of the most polluted cites in the world. Aerosol haze that appeared continuous from Beijing to Hong Kong is such an obvious sign of human industrial activity that it simply takes your breath away (literally). In places, even on a clear day, you cannot see the sun – even if there is no cloud in the sky. Only in the mountains or in deeply rural parts of the country was blue sky in evidence. This is clearly an unsustainable situation (even if you are only thinking about the human health impacts) and it points the way, I think, to how China can be engaged on the climate change front. If reducing aerosol emissions can be done at the same time that greenhouse gases can be cut, the Chinese will likely jump at the chance. As an aside, I noticed that Compact Florescent Light bulbs were being used almost everywhere you looked, and that the majority of Shanghai’s motorbikes and scooters were electric rather than gasoline powered. These efforts clearly help, but they are just as clearly not sufficient on their own.

Finally, the limited access to the Internet that one gets in China (through a combination of having better things to do with one’s time and the sometimes capricious nature of what gets through the Great Firewall) allowed me to take a bit of break from the constant back and forth on the climate blogs. In getting back into it, one appreciates just how much time is wasted dealing with the most ridiculous of issues (Hansen’s imagined endorsement of a paper he didn’t write thirty six years ago, the debunking of papers that even E&E won’t publish, and the non-impact of the current fad for amateur photography) at the expense of anything substantive. In effect, if possibly not in intention, this wastes a huge amount of people’s time and diverts attention from more significant issues (at least in the various sections of the blogosphere). Serious climate bloggers might all benefit from not getting too caught up in it, and keeping an closer eye on the bigger picture. We will continue to try and do so here.

I agree that this years Arctic Sea ice summer melt has been pretty memorable and, at least based on what we can interpret from the satellite record since 1979, certainly a record for the past 28 years. However, when you say:

“Observations from up here are astonishing, calm sea waters not freezing with -12 C surface temperatures”

RE #64, and I read solar & wind are beginning to become competitive with coal. And those many sq miles of solar could also include our roofs (which would help give extra insulation/shade for our homes, at least in sunny, hot areas).

Ah, just in the spirit of getting back to the original topic of the post, the emphasis on downcore records probably has a lot to do with how difficult is to get a deep sea sediment core, which involves renting an oil drilling ship (which is expensive), and then processing the core, which is time-consuming.

So, that shows why paleo studies are valuable – it gives you some idea of what conditions were like in the past, but you can’t just say that a 3C rise in surface temperatures would immediately flood the world with a 10-20 meter rise in sea level, because you can’t tell from looking at a multi-million year old sediment core (with tick marks measured in 1000’s of years, at least) how fast such transitions occurred.

Continuing:
“To test hypotheses that explain the end of the warm period, we compare distant palaeoceanographic records to examine tropical– extratropical interactions. This analysis results in the fundamental conclusion that major long-term cooling steps in different regions (for example, intensification of NHG (Northern hemisphere glaciation), reorganization of tropical circulation) did not all occur at the same time. Thus, regionally specific processes caused cooling phases at different times, and the end of the warm period was not forced by a single episodic event whose effects propagated globally.”

One take-home message here is that overly simplistic attempts to predict how the climate will respond are essentially useless. Here are the conclusions from Ravelo et. al regarding climate change. (The first point seems to be an example of what is happening in the Arctic right now, only it’s warming, not cooling)

“Implications for understanding climate change:

Several lessons can be drawn from the comparison of Plio-Pleistocene climate change records from distant locations.

*Second, the ventilated thermocline and/or latitudinal temperature gradient may have played an important role in linking subtropical conditions to change in other regions.

*Finally, tropical and subtropical conditions, specifically the time-averaged strength of coldwater upwelling in the eastern Pacific, and of Walker circulation, had a strong influence on the climate response to radiative changes.

Thus, the last 4Myr illustrates that as globally average conditions change, so do the feedbacks or ‘rules’ that determine climate sensitivity. This conclusion is relevant to studies of future global warming because it emphasizes the importance of ‘background’ or average tropical conditions in predicting high-frequency climate change. Furthermore, understanding processes responsible for recent climate change of the last hundreds or thousands of years, when average background conditions changed very little, is unlikely to be sufficient to predict climate variability for periods with different globally averaged conditions. This highlights the importance of developing theory to explain ocean and atmospheric change, and testing that theory using records from geologic time periods that represent a large dynamic range of climate conditions.”

Steve Sadlov, there is no point trying to minimize this year’s Arctic ice melting, which it appears you’re trying to do here, as you did on Tamino’s blog.
It is by all means astonishing. From satellites’ observations to research ships reports, to comparison with the oral traditions of local populations, it is obvious that this is an extremely unusual event. If one wonders what a tipping point might look like, this seems to be a good candidate. Your comments sound like you’re trying to say that it’s not all that bad. The cap is missing a chunk as big as Alaska (give or take, who cares). The Northwest and Northeast passages are completely irrelevant considering the huge missing piece of ice in the middle of the Arctic Ocean . You can try to nitpick a little detail here or there, so what?

Jim Cripwell,
Since you bring up the subject of peer review in science, we should emphasize that all peer review says is that the work appears correct and sufficiently interesting to a group of responsible experts that they deem it worthy of consideration by the wider community. The judgement on the work is whether the entire community of experts reaches a consensus that it is correct and valuable.

Steve Sadlov in #102 scratched his head about Wayne Davidson and queried the reliability of his observations. Well here’s your man, Wayne Davidson, resident of Resolute Bay, Nunavut Canada, and here’s evidence of the quality of his observations: http://www.eh2r.com/
Regarding the NE passage, the blockage Steve refers to is ~50% and from the images I’ve been watching even that may disappear in the next day or so.

And Davidson is reporting contrary to the Nunavut hierarchy. They rely on hunting polar bears. Or should I say selling hunts to prominent Texans? I will because they do. Naturally, they deny global warming and polar bear peril overall. What a shocker! Sadlov sees what he wants from Santa Maria. Have some tri-tip and look further out.

I’d suggest a need for scientific granting bodies to fund interdisciplinary think-tank research in addition to narrow focii. If the mandate is to maximize 21st century person-years, minimize economic costs, or drop GHG levels ASAP, there should be no political interference once initial funding is provided. Bringing together 3rd world researchers might be cheapest and least-biased.

Dr. Schmidt, when is the first time you heard the term Paleocene-Eocene Thermal Maximum? Does it seem plausible that perhaps this term has been created more to drum up research dollars than to convey real scientific meaning? Many readers may be interested to learn that the available deep ocean proxy record (oxygen isotopes) suggests that ice sheets in the Antarctic have generally been on the increase for the last 50 million years, with the notable exception being the Lower and Middle Miocene (12-24 million years ago. Readers might also be surprised to learn that the first bonafide evidence for the appearance of the East Antarctic ice sheet was during the Lower/Middle Eocene, about 49 million years ago, and very near the peak of the oxygen isotope depletion from the proxy record. Beginning at the K-T boundary, all the way up through Lower Oligocene, global sea levels averaged 100-200 meters higher than present. The proxy record convincingly points to a slow cooling trend for most of the last 50 million years!

If the climate community seeks another interesting climate, consider what I would dub the the Middle-Upper Miocene Shift (MUMS), 11 million years ago. Sounds worthy of research dollars, no? The Northern Hemisphere ice sheet had not yet emerged, yet the isotopes suggest dramatic increases in the growth of the Antarctic ice sheet, especially the West Antarctic ice sheet(supported by rock record). Notwithstanding the lack of NH ice, sea levels averaged about about where they are today, with some notable dramatic negative spikes about 8-10 mya, when sea levels dropped 20-100 meters below present levels(Mitchum et al., 1994). Moreover, the Upper Miocene deep ocean proxy record is punctuated by numerous small peaks, but no overall trend toward depletion or enrichment. Now forward to the Early Pliocene (Zanclean). There is a big highstand of sea level (50-100 meters higher than present), while at the same time, the first appearance of the NH ice sheet. Since then, there have been rapid succesions of glacial/interglacials, but mostly dominated by glaciation, and big lowstands of sea level. The isotope proxy follows, but shows an overall trend toward expanding ice sheets in the long run. So why this earth history lesson?

Here is an observation which hopefully spurs deep thought and further investigation: Integration of the sequence stratigraphic record (invented by some company called Exxon) and the proxy records suggests that regional polar climates dominate over bi-polar or global average climates. Melting ice in the NH can be (maybe the rule) taken up by increases in the SH, so that the direction and magnitude of sea level change is not straightforward or driven by a global mean climate or temperature. The take home message is that although we may have some more to go on the short term warming and sea level rise, the long term forecast is for ice, despite the human disturbance to the climate system. Our perturbation of the system, while signficant in many ways, in the long term is small and rapid compared to plate tectonics, the evolution of landforms, biota, biogeochemical changes, ocean overturning circulation, supervolcanoes, etc.

[Response: The PETM was coined around 2002 when the various official arbiters of the geological time scale defined this peak as the Paleocene-Eocene boundary. Prior to that it was called the Late (or Latest) Paleocene Thermal Maximum, and I think was first described by Kennett and Stott in 1991. The reason for it’s prominence is because of it’s intrinsic interest – the largest spike in d13C in the Cenozoic, the correlation with mammalian expansion, significant benthic extinction event etc. and also because the hypotheses for it’s occurrence (large inputs of carbon into the system, possibly from methane hydrates) does have implications for our current situation. For instance, how long does it take for sediments to fully absorb anomalous carbon? (about 100,000 years if the PETM is any guide).

Other periods in pre-quaternary climates are of interest as well, but it’s important to realise that you need not only an interesting event or period, but also a good hypothesis that can be tested tractably with current models – much of deeper time questions are not, and that limits their relevance for decadal to centennial climate changes in the future – and that is where most of the climate change money is. Various groups are pushing for a greater focus on the Pliocene (with some success) and the Eocene has always been in vogue (as a ‘hothouse’ climate), but MUMS probably has an uphill battle – I wish you luck! – gavin]

This article on the Sci Am website from studies of paleooceanic data suggest that warming oceans and not CO2 are responisble for the ending of ice ages (not sure if that is a issue for AGW or was not known) but is further suggests that climate sensitivity may be misunderstood at the present time due to the fact that present day warming is different from warming that causes the ice ages to end. deep sea water warmed first and then switched places with surface waters, today surface waters are warming first.

So it looks like there could be no precedent in the past for what is happenning now.

Re #99: “Let us get the facts right. Each year approximately 9 million sq kms of ice melt. Each year approximately 9 million sq kms refreeze. Since measurements started in 1979, approximately 35,000 sq kms extra ice has melted each year, and approximately 35,000 sq kms of ice has failed to refreeze, for a net loss of about 70,000 sq kms each year. This year about 10 million sq kms melted compared with 9 million normally.”
Shouldn’t that be 35,000 sq km extra melt and ~70,000 failed to refreeze?

I stand corrected, I misremembered the annual loss, it’s more like 15 year’s worth of melting in one summer not a decade! Here’s the August data, bear in mind the September data will be about 1million sq km less.

I lived in Southern California for three years and had to deal with the occasional smog problems. When I visited Bangkok, however, I found that I could barely breathe due to the persistent haze from vehicle traffic. And this was during the rainy season, which did little to clear the air before it became oppressive again!

Just a note Gavin, for perspective; I noted your jab at the “amateur” component of the surfacestations.org effort. Certainly I don’t deny that, in fact that is what makes the project work without the need for government funding.

Along those lines I’d point out that a significant portion of the surface temperature data you use in GISS, is in fact gathered by amateurs, at sites they self administer. And again, that is what makes it work without the need for government funding of observers. The US COOP network and other networks worldwide are largely staffed by volunteer amateur observers and the data they gather is important. I think we can all agree upon that.

Since a percentage your GISTEMP data effort then depends on the hard work of “amateurs”, perhaps then it would be wise to not paint other efforts that use data collected by amateurs in a negative light. As always, if there are suggestions that you have to offer that can improve the effort, I welcome them.

Just a note Gavin, for perspective; I noted your jab at the “amateur” component of the surfacestations.org effort.

No, he jabbed at the amateur photography component of your effort, not at amateur efforts in general.

There’s a world of difference between using amateurs to collect data, something that has a honorable history in the natural sciences, and pretending that a photograph (amateur or professional) is data.

Re #117: Interestngly enough, the NCDC scientists would actually like to have a good set of station photographs. One of the many reasons that the surfacestations.org effort appears to be less than interested in the actual science is that AW never got in touch with them to ask about methodology. But why do that if your pre-conceived intent is to turn around and do something with the photos that’s wholly unscientific, i.e. throw out all of the data from the “bad” stations? The fact is that various station biases (microsite, instruments, etc.) will be visible in the data. The photos can indeed come in real handy, but only as a way of trying to identify the source of a problem that’s already been seen in the data.

Another reason is that you persist in posting swill like this and then not retracting it when it’s proven bogus.

On Rod B.’s comment #98,the only ones dancing in the streets today are members of the American Petroleum Institute and the CEOs of Exxon Mobile.

The White House finished a two day conference on global warming and the administration firmly stated that the US wouldn’t cooperate on any internationally agreed to caps on CO2 emissions. In fact the Bush administration wants caps in the US to be voluntarily. This is a go it alone policy on a planetary problem. Volunteerism hasn’t worked in the past and it won’t work now.It will be no more effective than making drinking and driving voluntary.

There will be opportunists who will disregard any non mandatory guidelines. In order to remain competive,more responsible companies will have to follow the policies of the emitters. We’re stuck with business as usual for at least the next 15 months when this administration leaves.

RE #113: The Stott et al paper seems useful, but he used the publicity around it to peddle his somewhat contrarian agenda (which he and long-time collaborator Bob Thunell have expressed before). I really don’t see how he can support his claim about this study undermining sensitivity estimates, and fortunately the article you linked quoted Gavin to the opposite effect. That oceans warned first and emitted CO2 into the atmosphere has been uncontroversial for years, although the exact mechanism and timing remains an unsolved problem. See here for a much better discussion of the paper.

To demonstrate that all of this stuff is still at the blind-men-feeling-different-parts-of-the-elephant stage, see this discussion of a related paper from a few months ago. IMHO it was approximately as important as Stott et al and was also published in Science, but didn’t get as much attention since the authors didn’t load up the publicity with extraneous claims about the role of CO2 in the present warming.

In fact the Bush administration wants caps in the US to be voluntarily.

It’s worse than that – they still want voluntary emissions intensity targets, i.e. targets for the emissions:GDP ratio. They aren’t considering even voluntary targets for reductions in absolute GHG emissions levels.

Great comments, Gavin. I’ve been to mainland PRC a couple of times and to Hong Kong and even Hong Kong has a visible haze.

I live in Australia where the mainstream of politics despite noises to the contrary is firmly in denial because of their addiction to selling coal to China. My view is that China is really the place to start if we can get a handle on how to engage with decision makers. If Hansen’s views on the probability of multi-metre sea level rises should concern anyone, the Chinese should be at the head of the list. Shanghai for a start would be in deep (literally) trouble.

Ref 124. It was somewhat of an offhand remark. Since I am now 82, I dont expect to be around to either pay or clean up on such a bet. The basis might, however, be worthwhile talking about. In 2005, the supporters of AGW stated that the hurricane season in the North Atlantic was proof positive of global warming, just like the recent melt of arctic ice. In neither case is there any evidence that increased levels of CO2 has had anything to do with the observations. The Accumulated Cyclone Energy (ACE) for the NA was about 250 in 2005; the average is around 102; 2006 was around 75; 2007, year to date, is around 58. The same effect I certainly expect to see with arctic ice. Solar cycle 24 has still not started.

Welcome back Gavin, I have also been for 2 weeks around Singapore and the Philippines, mainly Manila and will give an up to date asessment of the pollution in those countries respectively.. Singapore is now like a computer game city, virtually no airbourne pollution that I could see, traffic was very light even on weekdays-you can go from Changi airport to the city in less than 20mins. Vehicles emmissions are checked regularly. Almost every apartment, office, and factory now has compact flouro lights and energy efficient water heaters. I was also there in 1992 and could see a huge diffence, then there was smog- quite heavy especially in the morning but now it’s virtually gone. We stayed with friends of my wife that have lived there for 5 years and say what I saw was typical of Singapore now. Manila unfortunately on the otherhand was still everything that Singapore is not. Jeepneys and trucks pumping out tonnes on choking black smoke from their antiquated japanese engines, traffic snarls that make LA look like a lil country town. The baranguays (small suburbs) are all covered with that familiar sooty black/grey residue from passing traffic. Consequently the air over the city is very very dirty! You can only imagine what that is doing to the cityfolks lungs. On the upside..most houses are using compact flouro lights and you wont find incandescent ones in shops anymore..I wish Australia took that idea.
Ps. I was in China for 4 weeks in 1989 (Tiannamen square time) and over every major city was thick smog..I believe that to have been caused largley by un-environmentally regulated factories and the crude coal burners most people used for cooking with.

Jim Cripwell,
You state that the scientific community trumpeted the 2005 hurricane season as “proof” of anthropogenic climate change. First, “they” did no such thing. The link between hurricanes and climate change is still not well understood. Some within the community believed that the 2005 season could be a preview of the future. Others did not. Consensus is absent. In any case, I know of no responsible scientists who made such a claim based on a single year’s hurricane activity.
Second, increased hurricane activity would merely be evidence that the energy in the climate system was increasing–not of why. Since even you admit that energy in the climate is increasing, and since the evidence for this is already overwhelming, there is no need to make such a claim.

Ray, well, there were too a bunch of scientists claiming the connection between AGW and the number of hurricanes in 2005. Don’t know (nor care) if they were a majority or not, but they won the decibel award, until, as you say, they were quieted by the more rational scientists of the AGW crowd. You may wish otherwise, but….. And I know, by your standards any scientist, by definition, was neither responsible nor credible if he/she so claimed a connection. And maybe they were the 2nd tier of scientists; I dunno.

WASHINGTON — Global warming, not natural fluctuations in ocean temperature, was the main cause of the ocean heat that energized last year’s killer hurricanes, scientists at a federally funded climate laboratory said Thursday.

As a result, continued increases in the Earth’s temperature likely will lead to more “enhanced hurricane activity” in future years, said climate analysts Kevin Trenberth and Dennis Shea of the National Center for Atmospheric Research in Boulder, Colo.

Ref 129. Pleasae refer to http://www.chesapeakeclimate.org/news/news_detail.cfm?id=104
As you will see there was a demand that Max Mayfield be fired because he would not agree that the 2005 hurricane season was not caused by global warming. I can remember the TV news broadcasts which said exactly the same thing.

If that’s the case then only bad things can happen.We either continue to increase GHG’s or we go into a recession or worse.

Secretary Rice said, at the conference at the White House, that global warming was a real global problem and that the U.S. was willing to lead the effort to reduce the emission of gases that lead to the warming. However, she also said that “Every country will make it’s own decisions…reflecting it’s own needs and interests.” Some leadership!

Jim #129 referred to the ‘scientific community’ and ‘responsible scientists’, I don’t think that the Hip Hop Caucus, Physicians for Social Responsibility or the Sierra Student Coalition were exactly what Ray had in mind..

*When snow melts at those high altitudes and then refreezes, it can absorb up to four times more energy than fresh, unthawed snow,…*

I think that’s the main message to be found there.

Obviously this will have consequences on internal ice lubrication, basal flow and friction effects and general warming of the ice caps, but that is beyond this study. I think the down-stream effects (literally) are apparent from other recent observations.

The Hip Hop Caucus, Physicians for Social Responsibility and the Sierra Student Coalition, a motley crew to be sure, were “quoting” others’ science, not their own. Such as (further in the referenced article) Casey DeMoss Roberts of the Sierra Club. “no fewer than four major scientific studies, published in peer-reviewed journals, have shown that increasingly warmer sea-surface temperatures worldwide are bolstering the frequency, power, and lifespan of major hurricanes.” Are they telling the truth? I dunno. But can’t be much worse than the reaction, Never heard of it! Never happened! Quit talking about it!

Then again maybe it can [:-( . The following is a call to action to a protest against global warming sponsored by The U.S. Climate Emergency Council: Noontime protest will include music, speakers, street theater and more….

RE: protesting against global warming. We are already seeing the climate warm & destabilize, and there’s also a good deal of warming to come even if we were to halt the use of fossil fuels overnight. Instead, how about some protests for the large-scale development of renewable energy? If we can spend $500 billion a year in the U.S. on say, the military budget, can’t we spend an equal amount on developing renewable energy? Can’t we give tax breaks to companies who start-up renewable energy firms? Can’t we encourage banks to make credit available to homeowners who want to put large solar PV systems on their roofs?

Protesting against global warming, at this point, is like protesting against a landslide that’s already started. We are going to have to adapt to warming above and beyond what we’re seeing today, regardless. We will also have to bring renewables online and quit burning fossil fuels as soon as possible. By doing that we can hopefully keep global warming to a manageable level.

Imagine shutting off all fossil fuel imports to the US (i.e. petroleum and natural gas) and shutting down all the coal-fired power plants as well. Come up with a technological and economic plan for replacing 50% of that energy with renewables. Figure out how to get by using far less energy than we do now by using efficient technology. That’s what needs to be done.

“A remarkable oxygen and carbon isotope excursion occurred in Antarctic waters near the end of the Palaeocene (~57.33 Myr ago), indicating rapid global warming and oceanographic changes that caused one of the largest deep-sea benthic extinctions of the past 90 million years. In contrast, the oceanic plankton were largely unaffected, implying a decoupling of the deep and shallow ecosystems. The data suggest that for a few thousand years, ocean circulation underwent fundamental changes producing a transient state that, although brief, had long-term effects on environmental and biotic evolution.”

Note to Bryan Sralla (I’m assuming?)
You say that: “Here is an observation which hopefully spurs deep thought and further investigation: Integration of the sequence stratigraphic record (invented by some company called Exxon) and the proxy records suggests that regional polar climates dominate over bi-polar or global average climates.”

Yes, well, Peter Vail’s work on stratigraphy with his Exxon colleagues was predated by L. Sloss, and it all relied on 19th century geology concepts. Are you implying that the stratigraphic work done with ocean cores could never be used to study paleoclimate because of Exxon’s involvement in stratigraphy studies?

Note that one of the main reasons we’re seeing rapid warming in the Arctic is increased heat transport from low latitudes, and the same thing is happening over the Antarctic Peninsula. Greenland is melting away, slowly but surely, and East Antarctica is holding steady (for now). Your theory of ‘regional polar climate domination’, which I assume means the theory that ice sheet dynamics control everything, hasn’t stood up well – you have to include CO2 as well. See Ice, Mud Point to CO2 Role in Glacial Cycle, Kerr, Science Sep15 2000, for example.

“Solar-cell technology proved too expensive for terrestrial use until the early 1970s when Dr. Elliot Berman, with financial help from Exxon Corporation, designed a significantly less costly solar cell by using a poorer grade of silicon and packaging the cells with cheaper materials.”

I’d be happy to see Exxon go back to solar PV – as long as they quit importing fossil fuels into the US.

In any case, claiming that “the long term forecast is for ice” is pretty meaningless. Will the Earth eventually head into another glacial cycle? That will probably be the case, since plate tectonics has moved landmasses over the polar regions, and that won’t change anytime soon. Could we postpone the next glacial cycle? If the PETM recovery (carbon uptake by sediments) took 100,000+ years, then yes, we could. A recently published separate line of evidence based on marine (bio)chemistry models supports this notion. ( abstract here )

In the long run, our sun will turn into a red giant, and will burn the Earth to a crisp. It’s the short term decades-to-centuries scale that we’re all concerned about here.

Fair enough with the criticisms. Getting back to arctic ice. Is there general agreement amongst the proponents of AGW, that this year’s dramatic decrease in the minimum ice conditions in the arctic in September 2007, is proof positive of AGW?

[Response: That’s not how it works. If this year had been a complete anomaly in an otherwise trendless series, it would be curious but not definitive in any sense. However, it occurred in the context of a sharp and accelerating downward trend and comes on the heels of a number of recent records, thus it seems very consistent with the longer term picture – and that is what climate scientists are looking at. Nothing on it’s own is ‘proof positive’ – and frankly never will be. But the accumulation of all these projected (or in this case worse-than-projected) effects adds substantially to confidence in the big picture. – gavin]

) Casey DeMoss Roberts of the Sierra Club. “no fewer than four major scientific studies, published in peer-reviewed journals, have shown that increasingly warmer sea-surface temperatures worldwide are bolstering the frequency, power, and lifespan of major hurricanes.” Are they telling the truth? I dunno. But can’t be much worse than the reaction, Never heard of it! Never happened! Quit talking about it!

The point, Rod B, is that the scientific papers that are mentioned talk about trends, not an individual year such as 2005.

It wouldn’t be incorrect to state that there’s evidence that years like 2005 will become increasingly likely due to global warming. But if anyone has quoted papers such as this to claim that “the 2005 hurricane season was caused by global warming”, well, that’s their problem, not the scientists who are talking about possible trends.

“Using measurements of time-variable gravity from the Gravity Recovery and Climate Experiment satellites, we determined mass variations of the Antarctic ice sheet during 2002–2005. We found that the mass of the ice sheet decreased significantly, at a rate of 152 +/- 80 cubic kilometers of ice per year, which is equivalent to 0.4 +/- 0.2 millimeters of global sea-level rise per year. Most of this mass loss came from the West Antarctic Ice Sheet.”

Given the rapid and apparently unexpected current rate of warming in the Arctic, things might start proceeding faster in the Antarctic as well. The West Antarctic sheet will certainly melt first.